Association between the 400-m walk test and sensor-based daily physical activity in frail and sarcopenic older adults

Physical activity (PA) is recommended for frail and sarcopenic older adults as an essential means of preventing negative health outcomes and decline in functional abilities. Our objective was to examine the association between the time and/or stops during the 400-m walk test (400MWT) and average daily steps and walking cadence in a German cohort of frail and sarcopenic community-dwelling older adults.

For this sub-study the German cohort of 104 frail and sarcopenic older adults (i.e., SPRINTT) aged 80.8 ± 5.2 years was divided into participants having made none or one stop or more than one stops, referred to as non-stoppers and multi-stoppers. The characteristics and general health state (physical function, disease state, concerns about falling) at first observation (FO) and individual last observation (LO) after at least 11 months (mean 24.5 ± 8.5 months) were examined. Daily PA represented by average daily steps and walking cadence was assessed over three to seven days at FO and LO using the activPAL3 micro. Time and stops made during the 400MWT and their association with daily PA were investigated using regression with bootstrapping.

Out of 104 frail and sarcopenic older adults, 84 non-stoppers (female: n = 54; 64.3%) had a median time in 400MWT of 509 s (Inter Quartile Range (IQR) 324-875), a median number of daily steps of 6537 (IQR 1841-19,488) and a median daily walking cadence of 73 steps/minute (IQR 53.3-88.9). 20 multi-stoppers (female: n = 12; 60%) showed a time of 703 s (IQR 479-898), 5642 steps (IQR 2470-11,458) and a cadence of 70.7 steps/minute (IQR 61.4-83.6). Time was significantly associated with average daily steps and walking cadence at both FO and LO, stops alone were not.

Gait speed under laboratory conditions can be used in clinical settings and research to estimate daily PA, represented by average daily steps and cadence, in frail and sarcopenic older adults.